Development of a fiber-optic sensor based on surface plasmon resonance on silver film for monitoring aqueous media

A reliable fiber-optic SPR sensor based on silver is developed in this pape r for chemical and biological applications. The range of measurable indices is shifted down by coating an overlay of zirconium acetate on the silver s urface by sol-gel technique. The feasibility has been investigated in advan ce by theoretical analyses. The experimental fiber-optic sensor demonstrate s its capability to operate in the aqueous media with the detectable range of refractive indices of 1.33-1.36. A self-assembled monolayer (SAM) of lon g chain thiol is introduced to cover the surface of silver in order to prev ent silver from deterioration. Experimental studies demonstrate that in thi s way, the sensor lifetime increases from days to weeks. This work provides a base for developing an affinity biosensor. (C) 2001 Elsevier Science B.V . All rights reserved.